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Area forecast discussion 
National Weather Service Pueblo Colorado
427 am MDT Sat Apr 25 2015

Short term...(today and tonight)
issued at 348 am MDT Sat Apr 25 2015

..major Spring storm to start affecting the region starting later


Regional radars showing showers increasing over the western slope as
a lead short wave associated with a major trough over the western
Continental U.S. Moves towards the region. Locally...skies predominantly clear
over the area with temperatures in the 40s plains and 20s to 40s


Trough over the western Continental U.S. Will continue to dig and amplify into
a full latitude trough through the next 24h. By 00z (6 PM this
evening)....trough axis will be located over the Nevada/Utah border.
Surface low pressure will slowly evolve over the southeast Colorado plains this
afternoon...and surface winds will transition from westerly this morning
to south-southeasterly by later this afternoon. Showers and
thunderstorms will gradually increase over the Continental Divide this morning
and become likely by this afternoon as lead wave moves east. This
scattered precipitation activity will move to the plains/mountains interface by late

We will likely see some thunderstorm activity over the burn scars
late today and this evening...and these areas will have to be
watched for locally heavy rainfall.


As wave interacts with better moisture over the plains of eastern
Colorado...thunderstorm activity will increase over northeast Colorado.
Models indicate that this activity will build southward and will
likely affect parts of our far eastern plains this evening. Storm Prediction Center has
area in marginal risk as cape and shear are marginally favorable for
producing severe weather. Would not be too surprised to see a severe
thunderstorms and rain watch this evening...but do not know how far south the severe
threat will exist. Best chance of storms on the far east plains
tonight will be over Kiowa County.

Clouds will increase over the plains tonight with lower ceilings likely
after midnight. It will be mild tonight with the cloudiness.

Over the mountains...precipitation activity will likely decrease a bit as weak
downward vertical motion moves in in advance of the primary trough
that will be moving towards the region late tonight.

I expect that we will see 1-3 inches of snow across the Continental Divide
tonight...especially elevations above 10000 feet. The San Juans will
be most favored.

Long term...(sunday through friday)
issued at 348 am MDT Sat Apr 25 2015

..significant precipitation expected across southern Colorado...

Models in good agreement with low ensemble spreads through much of
the extended with high confidence in widespread heavy
precipitation in the Sunday to Monday time frame.

Sunday and Monday...models and ensembles drop an upper level
storm system south out of the Pacific northwest and across central
New Mexico...and into the Texas Panhandle. The storm path is
highly favorable for widespread precipitation across southern
Colorado. This storm has the potential to produce several hazards
across the area...from heavy mountain snow...strong thunderstorms
over the plains and localized flooding.

Strong to severe weather threat Sunday afternoon...models develop
a surface low near Trinidad Sunday morning with a boundary setting
up from near Pueblo...southeast to near Springfield. Locations
south of this boundary will likely destabilize through the early
afternoon with around 1000 j/kg of cape possible. Given the shear
and dynamics of the upper system...storms will rotate...with
strong winds and near severe hail possible. The window of
opportunity for strong to severe storms is small...but the
potential will exist early Sunday afternoon.

Heavy snow potential Sunday into Monday...the main question will
be snow levels. Where its cold enough...its going to snow. This
storm system is not overly cold. Snow levels will likely remain
confined to above 7-8 kft. Above this level...heavy wet snow will
fall. The storm track and flow around the upper system to the
south provide the focus for heavy snow along the Lee slopes of the
eastern mountains. Have hoisted winter storm watches for the
sangre Delaware cristo and Wet Mountains along with Pikes Peak. This
snow will be wet and heavy...and tree damage is likely. Snow is
also expected along the Continental Divide. The storm path is a
bit less favorable for higher snow totals there...however a few
inches of snow are possible. The San Juan range may be the
exception an this will need to be monitored. In addition to the
heavy snowfall...there will likely be an elevated avalanche
threat. If you are traveling in the mountains...especially the
eastern prepared for hazardous winter travel

Heavy rain Sunday into Monday...models in good agreement with
storm track across central New Mexico...which provides the focus
for deep and strong upslope flow across the eastern plains while
advecting rich moisture into the area. The lower elevations of
the eastern mountains and locations south of Highway 50 will see
the heaviest rainfall...where up to 2 inches...if not
likely. Locations north of Highway 50 will still see rain with
around an inch possible. These rainfall amounts could lead to
localized areas of runoff flooding and this potential will need to
be monitored closely.

This storm will bring significant impacts to southern Colorado.
Prepare for the snowfall if you live in the higher
elevations...and be ready for wet travel conditions across the
eastern plains.

Tuesday through Friday...the upper level storm system is forecast
to move away from the area Monday night into Tuesday with high
pressure over the Great Basin building into Colorado. Drier
conditions are expected to prevail with daily afternoon and
evening showers and thunderstorms for the mountain areas. Steering
flows will be weak Tuesday through Thursday with little movement
off the mountains expected. Southwest flow is forecast to increase
by Friday with increasing moisture into the weekend. More
widespread shower and thunderstorms are expected Friday with
activity moving into the I-25 corridor Friday afternoon. After a
couple of cooler days Sunday and Monday...temperatures will be
back into the 70s and lower 80s for the rest of the week. Mozley


Aviation...(for the 12z tafs through 12z Sunday morning)
issued at 348 am MDT Sat Apr 25 2015

VFR conditions likely through at least midnight (06z/26th) at all 3
taf sites (kcos...kals and kpub). We could see some isolated thunderstorms and rain this
afternoon and evening at any of the three sites.

Later tonight...upslope flow increases on the plains and we may see
low ceilings/fog at kpub and kcos after midnight. Isolated rain showers will also
be possible.

Surface winds will be light at all 3 taf sites.

For planning purposes...a major Spring storm will affect the entire
region Sunday into Monday. Heavy precipitation is likely with low ceilings.
Still needs to be determined if it will be snow at any of the taf
sites (especially Sunday night/early monday) but it is not out of
the question.


Pub watches/warnings/advisories...
Winter Storm Watch from Sunday morning through Monday afternoon
for coz072>075-079-080-082.



Short term...hodanish
long term...mozley

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